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Tuning microstructures of Mg-Ce-Ni hydrogen storage alloys via Cu and carbon nanotube additions

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Nano Research 2024年第8期17卷 7203-7211页

作者： Linlin Zhang Liang Xiong Bingyang Gao Qingyun Shi Ying Wang Zhiya Han Zhenhua Zhang Chunli Wang Limin Wang Yong Cheng State Key Laboratory of Rare earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China Purification Equipment Research institute of csic Handan 056002China

Mg-based alloys are regarded as highly promising materials for hydrogen *** significant improvements of the properties for Mg-based alloys,challenges such as slow hydrogen absorption/desorption kinetics and high thermodynamic stability continue to limit their practical *** this study,to assess hydrogen storage alloys with enhanced properties,incorporating both internal microstructure modulation through the preparation of amorphous/nanocrystalline structures and surface property enhancement with the addition of Cu and carbon nanotubes(CNTs),the kinetic properties of activation and hydrogenation,thermodynamic properties,and dehydrogenation kinetics are *** results reveal a complementary interaction between the added Cu and CNTs,contributing to the superior hydrogen storage performance observed in sample 7A-2Cu-1CNTs with an amorphous/nanocrystalline structure compared to the other experimental ***,the samples are fully activated after the initial hydrogen absorption and desorption cycle,demonstrating outstanding hydrogenation kinetics under both high and low temperature experimental *** noteworthy is that the hydrogen absorption exceeds 1.8 wt.% within one hour at 333 ***,the activation energy for dehydrogenation is decreased to 64.71 kJ·mol^(–1).This research may offer novel insights for the design of new-type Mg-based hydrogen storage alloys,which possess milder conditions for hydrogen absorption and desorption.

关键词： Mg-Ni-Ce alloy hydrogen storage amorphous/nanocrystalline structure kinetics Cu and carbon nanotubes(CNTs)codoping

Numerical evaluations on the fluid production in the in-situ conversion of continental shale oil reservoirs

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Petroleum Science 2024年第4期21卷 2485-2501页

作者： Zhao-Bin Zhang Maryelin Josefina Brice?o Montilla Shou-Ding Li Xiao Li Jian-Peng Xing Yan-Zhi Hu Key Laboratory of Shale Gas and Geoengineering Institute of Geology and Geophysics Chinese Academy of Sciences institute of earth Sciences Chinese Academy of Sciences College of earth and Planetary Sciences University of Chinese Academy of Sciences institute of Energy Peking University

In-situ conversion presents a promising technique for exploiting continental oil shale formations,characterized by highly fractured organic-rich rock. A 3D in-situ conversion model, which incorporates a discrete fracture network, is developed using a self-developed thermal-flow-chemical(TFC) *** of the model elucidates the in-situ conversion process in three stages and defines the transformation of fluids into three distinct outcomes according to their end stages. The findings indicate that kerogen decomposition increases fluid pressure, activating fractures and subsequently enhancing permeability. A comprehensive analysis of activated fracture permeability and heating power reveals four distinct production modes, highlighting that increasing heating power correlates with higher cumulative fluid production. Activated fractures, with heightened permeability, facilitate the mobility of heavy oil toward production wells but hinder its cracking, thereby limiting light hydrocarbon ***, energy efficiency research demonstrates the feasibility of the in-situ conversion in terms of energy utilization, especially when considering the surplus energy from high-fluctuation energy sources such as wind and solar power to provide heating.

关键词： In-situ conversion Continental shale oil Natural fracture network TFC model

A novel(Sm0.2Eu0.2Gd0.2Ho0.2Yb0.2)CrO3 high-entropy ceramic nanofiber as a negative temperature coefficient thermistor

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Journal of Rare earths 2024年第10期42卷 1937-1942页

作者： Weijun Zhao Meng Zhang Liyan Xue Kaixian Wang Fan Yang Jiuping Zhong Heng Chen School of Materials Sun Yat-sen University Xiamen institute of Rare earth Materials Haixi InstituteChinese Academy of Sciences Xiamen Key Laboratory of Rare earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstituteChinese Academy of Sciences Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China Advanced Energy Science and Technology Guangdong Laboratory Sichuan Jcc Rare earth Metals New Material Co. Ltd.

The electrical properties of high-entropy ceramics（HECs） have been extensively studied in recent years due to their unique structural characteristics and fascinating functional properties induced by entropy *** high-entropy(Sm0.2Eu0.2Gd0.2Ho0.2Yb0.2)CrO3（HE-RECrO3） nanofibers were prepared by electro *** work demonstrates that HE-RECrO3nanofibe rs were successfully synthesized at a low temperature（800℃）,which is approximately 400 ℃ lower than the temperatures at which chromate ceramics were synthesized via the sol-gel method and the solid-state reaction *** resistivity of HE-RECrO3nanofibers decreases exponentially with increasing temperature from 25 to600℃.The logarithm of the resistivity is linearly related to the inverse of the temperature,confirming the negative temperature coefficient property of *** B25/50value of the HERECrO3nanofibers reaches 4072 *** conclusion,HE-RECrO3nanofibers are expected to be potential candidates for negative-temperature-coefficient（NTC） thermistors.

关键词： Ceramic fiber materials High-entropy ceramics Negative temperature coefficient thermistors Rare earths

Water and other volatiles on Mars

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National Science Review 2024年第6期11卷 12-14页

作者： Sen Hu Yubing Gao Zhan Zhou Liang Gao Yangting Lin Key Laboratory of the earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of Sciences College of earth and Planetary Sciences University of Chinese Academy of Sciences

Mars, the intriguing red planet, is one of the planets most similar to the earth in our solar system. It is widely accepted that Mars could have had a warm and wet climate in its early history supported by numerous lines of evidence, e.g. topography, canyons, outflow channels, presence of phyllosilicates and evaporative salts,sedimentary formation, and many others (e.g.[1]), and thus Mars is believed to once have a potentially habitable environment which could be able to supply fundamental conditions for the evolution of potential lives.

关键词： ISOTOPIC COMPOSITION MARTIAN ATMOSPHERE SUBSURFACE WATER ABUNDANCE TISSINT H2O CO2

Two decades of fire activity over the PEEX domain:a look from space,with contribution from models and ground-based measurements

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Big earth Data 2024年第2期8卷 350-396页

作者： Larisa Sogacheva Timo H.Virtanen Anu-Maija Sundström Pekka Kolmonen Mikhail Sofiev Hanna K.Lappalainen Antti Arola Finnish Meteorological institute Climate Research ProgrammeHelsinkiFinland Finnish Meteorological institute Space and Earth Observation CentreHelsinkiFinland institute for Atmospheric and earth System Research/Physics Faculty of ScienceUniversity of HelsinkiHelsinkiFinland

It has been suggested that forest fires will become more frequent/intense with changing climate,which would increase aerosol/gas emissions into the atmosphere.A better under-standing of the relations between meteorological conditions,fires,and fire emissions will help estimate the climate response via forest *** this study,we use ERA5 meteor-ological products,including temperature,precipitation,and soil moisture,to explain the frequency of forest fires and the amount of radiant energy released per time unit by burning vegetation(fire radiative power,FRP).We explore the relation-ships between satellite-retrieved fire products and aerosol properties(aerosol optical depth,AOD),carbon monoxide(CO),formaldehyde(HCHO),and nitrogen dioxide(NO_(2))con-centrations over the PEEX domain,which covers different vegetation zones(***/grasslands,forest,arctic tun-dra)of Pan-Eurasia and *** analyse the concentrations of black carbon and absorbing organic carbon using groundbased AErosol RObotic *** analysis covers the months of May to August from 2002 to *** show posi-tive temperature trends in the Northern zone(>65°N)in June and August(1.56°C and 0.64°C,respectively);all statistically significant trends for precipitation and soil moisture are *** can explain increased fire activity in Siberia over the recent years(2019-2022).Over the whole PEEX domain,FC and FRP trends remain insignificant or negative;a decrease in AOD may address those negative *** show that intrasummer variations exist for cropland/grassland fires,which occur most often in May and August,while Siberian forest fires occur more often in July and *** show that CO concentration has been gradually decreasing in the last two decades in May and *** trends are negative in May,June,and over summer for all regions,in July in Europe,China,the Southern zone(<55°N),and the PEEX *** trends are not significant in all ***_(2)trends are positive in May and

关键词： PEEX wild fires satellite trend enhancement ratios

Nitrogen isotope stratigraphy of the Early Cambrian successions in the Tarim Basin:Spatial variability of nitrogen cycling and its implication for paleo-oceanic redox conditions

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Acta Geochimica 2024年第4期43卷 785-801页

作者： Bi Zhu Xuefeng Li Lu Ge Yongquan Chen institute of earth’s Critical Zone School of Earth Sciences and EngineeringHohai UniversityNanjing 210098China Research institute of Exploration and Development Tarim Oil Field CompanyPetroChinaKorlaChina

The Early Cambrian represents a critical time period characterized by extraordinary biological innovations and dynamic redox conditions in *** isotopic signatures of ancient sediments have the potential to elucidate the evolutionary path of marine redox states and the biogeochemical nitrogen cycle within the water column of the Early Cambrian *** existing research on this topic has predominantly focused on South China,the exploration of other continental margins has been limited,leaving contradictory hypotheses *** this study,pairedδ^(15)N andδ^(13)C org analyses were performed on the Lower Cambrian successions from the Shiairike section(inner ramp)and Well Tadong 2(deep shelf/basin)in the northwestern and eastern Tarim Basin,*** data from the Shiairike section reveal a discernible shift in the operation of different nitrogen cycles for the black chert-shale unit,also referred to as the black rock series in Chinese literature,of the Yurtus Formation(Fortunian stage to lower Stage 3).Oscillatingδ^(15)N values for its lower part are suggestive of alternating anaerobic assimilation of NH 4+and denitrification/*** is likely attributed to a shallow,unstable chemocline consistent with the upwelling and incursion of deep,anoxic waters during a major *** contrast,aerobic nitrogen cycling,indicated by positiveδ^(15)N values of>2‰,dominated the upper part alongside a reduction in upwelling *** the other hand,theδ^(15)N signatures of Xishanbulake and Xidashan Formations of Well Tadong 2,which encompass a time interval from the Cambrian Fortunian Age to Age 4,are indicative of N_(2)fixation by diazotrophs as the major nitrogen *** two studied intervals,although not time-equivalent,exhibit separated states of nitrogen cycling at least during the deposition of the Yurtus black rock *** spatially different nitrogen cycling of the studied sections is compatible with a redox-stratified ocean dur

关键词： Nitrogen isotopes Early Cambrian Tarim Black rock series

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Deep carbon recycling viewed from global plate tectonics

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National Science Review 2024年第6期11卷 37-55页

作者： Maoliang Zhang Sheng Xu Yuji Sano School of earth System Science Tianjin University Marine Core Research institute Kochi University Atmosphere and Ocean Research institute The University of Tokyo

Plate tectonics plays an essential role in the redistribution of life-essential volatile elements between earth's interior and surface, whereby our planet has been well tuned to maintain enduring habitability over much of its history. Here we present an overview of deep carbon recycling in the regime of modern plate tectonics,with a special focus on convergent plate margins for assessing global carbon mass balance. The up-to-date flux compilation implies an approximate balance between deep carbon outflux and subduction carbon influx within uncertainty but remarkably limited return of carbon to convecting mantle. If correct, carbon would gradually accumulate in the lithosphere over time by（i） massive subsurface carbon storage occurring primarily in continental lithosphere from convergent margins to continental interior and（ii） persistent surface carbon sinks to seafloors sustained by high-flux deep CO2emissions to the atmosphere. Further assessment of global carbon mass balance requires updates on fluxes of subduction-driven carbon recycling paths and reduction in uncertainty of deep carbon outflux. From a global plate tectonics point of view, we particularly emphasize that continental reworking is an important mechanism for remobilizing geologically sequestered carbon in continental crust and sub-continental lithospheric mantle. In light of recent advances,future research is suggested to focus on a better understanding of the reservoirs, fluxes, mechanisms, and climatic effects of deep carbon recycling following an integrated methodology of observation, experiment,and numerical modeling, with the aim of decoding the self-regulating earth system and its habitability from the deep carbon recycling perspective.

关键词： deep carbon recycling convergent plate margins subduction continental reworking global carbon mass balance

Multiscale spatiotemporal meteorological drought prediction:A deep learning approach

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Advances in Climate Change Research 2024年第2期15卷 211-221页

作者： Jia-Li ZHANG Xiao-Meng HUANG Yu-Ze SUN Department of earth System Science Ministry of Education Key Laboratory for Earth System ModellingInstitute for Global Change StudiesTsinghua UniversityBeijing 100084China

Reliable monitoring and thorough spatiotemporal prediction of meteorological drought are crucial for early warning and decision-making regarding drought-related *** utilisation of multiscale methods is effective for a comprehensive evaluation of drought occurrence and progression,given the complex nature of meteorological ***,the nonlinear spatiotemporal features of meteorological droughts,influenced by various climatological,physical and environmental factors,pose significant challenges to integrated prediction that considers multiple indicators and time *** address these constraints,we introduce an innovative deep learning framework based on the shifted window transformer,designed for executing spatiotemporal prediction of meteorological drought across multiple *** formulate four prediction indicators using the standardized precipitation index and the standard precipitation evaporation index as core methods for drought definition using the ERA5 reanalysis *** indicators span time scales of approximately 30 d and one ***-term indicators capture more anomalous variations,whereas long-term indicators attain comparatively higher accuracy in predicting future *** focus on the East Asian region,notable for its diverse climate conditions and intricate terrains,to validate the model's efficacy in addressing the complexities of nonlinear spatiotemporal *** model's performance is evaluated from diverse spatiotemporal viewpoints,and practical application values are analysed by representative drought *** results substantiate the effectiveness of our proposed model in providing accurate multiscale predictions and capturing the spatiotemporal evolution characteristics of *** of the four drought indicators accurately delineates specific facets of the meteorological drought ***,three representative drought events,namely flash drought,sustained drought and severe drought,

关键词： Meteorological drought Spatiotemporal prediction Multiscale Swim transformer Deep learning

Key issues on magnetic reconnection at Mercury

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earth and Planetary Physics 2024年第5期8卷 673-685页

作者： Jun Zhong Key Laboratory of earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences

Magnetic reconnection processes and their impact on planetary magnetospheric dynamics exhibit significant differences due to differences in upstream solar wind conditions and internal planetary environments. Current understanding of reconnection phenomena at Mercury is rooted in the MESSENGER mission. However, direct detection of reconnection remains rare. Here, we aim to assess the limitations of MESSENGER in detecting reconnection in Mercury's space and to discuss key issues of reconnection that will be addressed by BepiColombo, including the dynamics of magnetic flux ropes, particle acceleration, density asymmetric reconnection,IMF-driven near-tail structures, and potential modes of magnetospheric convection.

关键词： magnetic reconnection Mercury MESSENGER BepiColombo